Threaded post with negative ribs

Abstract

A nut and bolt fastens two perforated flat plates by threading fully into a nut on the opposing side of the plates. A threaded post, emanating from a flat, threaded into a complementarily threaded post hole cannot be equipped with strengthening features such as chamfers, fillets, or ribs because these devices block the strengthened threaded post from being fully threaded through perforated plates into a threaded posthole. The negative rib is a concavity spanning the orthogonal join between the post and the flat from which it emanates, and provides the same benefits that a regular rib provides, including discontinuity of join between post and flat, a variable distribution of forces amongst a more complex boundary area between post and flat, and the ability to increase the number, width, and depth of negative rib to achieve design objectives. The negative rib can also be decorated with fillets further strengthening the post against dehiscion from the flat to which it is attached.

The following claims are made about the invention described in this application: 
     
         1 . A cylindrical post emanating from a larger flat surface, wherein:
 a plurality of cavities are distributed in a circular pattern about the cylindrical axis of the post, each cavity spanning the join of the post to the larger flat surface but not perforating either surface into which it is formed.   
     
     
         2 . A post as claimed in  claim 1 , wherein:
 the post is externally threaded, excepting the spaces comprised by said plurality of cavities, thus forming a discontinuous yet functional thread.   
     
     
         3 . A threaded post as in  claim 2 , wherein:
 edges of said plurality of cavities are filleted to provide further strengthening against dehiscion of the post.